For a vehicle performing transportation work on the premises of a facility handling a radioactive material, the radioactive material may adhere to the vehicle surfaces. Therefore, in order to prevent the radioactive material from spreading out of a given predetermined zone, there is a need for an apparatus capable of inspecting vehicles that have finished work in the zone and are to leave the zone for the presence/absence of a contamination state (radioactive contamination) of the radioactive material.
There is related art in which the presence/absence of radioactive contamination on a vehicle, which is the inspection target, is judged (e.g., refer to Patent Literature 1). In Patent Literature 1, under a state in which a mobile unit is stationary, the presence/absence of contamination is detected by an upper surface detection unit, a right-side surface detection unit, and a left-side surface detection unit in the mobile unit. The presence/absence of contamination on the three surfaces, namely, the upper surface, the right-side surface, and the left-side surface, is detected by moving the mobile unit and repeating detection at the remaining places.
In Patent Literature 1, the presence/absence of contamination on the front surface and the rear surface of the vehicle is detected by a front surface detection unit and a rear surface detection unit, which respectively are arranged as separate components to the mobile unit. As a result, detection for the presence/absence of contamination is performed for all of the surfaces of the vehicle to be inspected, and when contamination is not detected on any of the front surface, the rear surface, the right-side surface, the left-side surface, and the upper surface, such a vehicle is judged as having no contamination.